Business Tax Deadlines (2024 Returns and 2025 Payments)

Key business tax dates at a glance

For many businesses, 2024 federal returns are due in 2025. Sole proprietors and calendar-year C corporations generally file by April 15, 2025. Partnerships and S corporations generally file by March 17, 2025, because March 15 falls on a Saturday.

These dates cover federal returns, not every tax a business may owe. Payroll, excise, sales, and state taxes can follow separate schedules. Check the form instructions and your state tax agency before relying on a federal date.

For 2025 estimated income tax, common due dates are April 15, June 16, September 15, and January 15, 2026. The June date moves from June 15 because that day is Sunday. The January payment covers income earned late in 2025.

• March 17, 2025: Form 1065 partnership returns and Form 1120-S S corporation returns.
• April 15, 2025: Individual returns, sole proprietor Schedule C filings, and calendar-year C corporation returns.
• Estimated payments: April 15, June 16, September 15, 2025, and January 15, 2026.

Dates can shift when a deadline falls on a weekend or federal holiday. The IRS lists its key business tax calendar dates and notes relevant filing periods.

Corporate tax deadlines explained

Many owners search for a March 15 business tax deadline. For 2025, March 15 is a Saturday, so calendar-year partnerships and S corporations generally file on Monday, March 17. Their returns report business income and pass each owner’s share through to an individual return.

Partnerships file Form 1065. S corporations file Form 1120-S. These entities often give owners a Schedule K-1, which reports each owner’s share of income, deductions, and credits. Owners may need that form before they can finish their own returns.

A calendar-year C corporation generally files Form 1120 by April 15, 2025. A corporation with a different tax year usually files by the 15th day of the fourth month after its year ends. Check the form instructions when a year-end differs from December 31.

For a quick comparison, use the business’s tax year and legal structure. Do not assume that the owner’s personal filing date also applies to the entity return. The IRS explains filing rules for different business tax forms.

Deadlines by business structure

A sole proprietor usually reports business income on Schedule C with Form 1040. For a 2024 calendar-year return, the due date is April 15, 2025. A single-member limited liability company often follows this same federal filing path unless it elects corporate tax treatment.

Partnerships and S corporations generally file their 2024 returns by March 17, 2025. They pass income details to owners, who report those amounts on their own returns. If an owner needs more time to file, that does not extend the entity’s filing deadline.

Calendar-year C corporations generally file their 2024 returns by April 15, 2025. Businesses with a fiscal year may have a different date. Verify the year-end shown on the return before setting reminders.

Business type	Typical federal return	2024 return due date
Sole proprietor	Form 1040 with Schedule C	April 15, 2025
Partnership	Form 1065	March 17, 2025
S corporation	Form 1120-S	March 17, 2025
Calendar-year C corporation	Form 1120	April 15, 2025

For the 2024 filing calendar, partnership and S corporation returns were generally due March 15, 2024. Individual and sole proprietor returns were generally due April 15, 2024. These are past dates, but they help explain why a 2024 business tax deadline can mean either a filing date in 2024 or a 2025 filing for 2024 income.

What a tax extension does - and does not do

An extension gives more time to file a return. It does not give more time to pay tax due. If you expect to owe personal income tax, pay by April 15, 2025, even if you request an extension.

Many individuals request more time by filing Form 4868. The usual extended filing date is October 15, 2025. Partnerships and corporations request more time with Form 7004. A timely business extension often adds six months, but the exact date depends on the return and tax year.

Estimate what you owe before the original deadline. Pay as much as you can by that date, then file the extension form on time. Keep proof of the request and payment with your tax records.

An extension does not pause estimated tax payments or change separate payroll tax dates. If your business has a different year-end, check its specific extension deadline. Use the IRS form instructions rather than assuming every return gets the same extra time.

What happens when you miss a deadline

Late filing and late payment can lead to different IRS penalties. A return filed late may face a failure-to-file penalty. Tax paid late may face a failure-to-pay penalty, plus interest on unpaid amounts. The balance can grow while it remains unpaid.

Partnerships and S corporations may owe penalties for late returns, even when the entity itself does not pay federal income tax. The amount can depend on how many owners the business has and how long the return is late. Filing promptly can limit added charges.

If you missed a date, file the return as soon as you can and pay what you can. Do not wait until you can pay the full balance. Ask the IRS about payment options if you cannot pay in full, and keep records of any notice or response.

The IRS may waive some penalties when a business can show reasonable cause. Relief is not automatic, and interest may still apply. Read the IRS guidance on late filing penalties to understand the rules that may apply to your case.

Ways to stay on time and meet state rules

Build one tax calendar for each entity and owner. Include return dates, estimated payments, payroll filings, and state deadlines. Set reminders at least a month before each due date, then assign one person to check that each task is complete.

Keep income records, expense receipts, payroll data, and owner details current throughout the year. Reconcile bank records each month and save tax forms as they arrive. This makes it easier to prepare returns and spot missing information before a filing date.

Estimated tax payments matter when you expect to owe tax that is not covered by withholding. Use the April 15, June 16, and September 15, 2025 dates, then plan for January 15, 2026. Your required payment can depend on prior-year tax and current-year income, so review the IRS rules or ask a tax professional.

State dates may differ from federal dates, and some states use different rules for extensions or estimated payments. Check each state where the business files or earns income. Confirm current-year instructions, since deadlines can change after weekends, holidays, or local emergencies.

For a small business, the safest habit is simple: confirm the right form, calendar the original due date, and pay any expected tax on time. A filing extension can ease the paperwork rush, but it cannot replace a payment plan.